Overheating; Engine; Cooling System; Fuel System - Yamaha CS50 Service Manual

EAS00855

OVERHEATING

ENGINE

Clogged coolant passages
• Cylinder head(s) and piston(s)
• Heavy carbon buildup
Engine oil
• Incorrect oil level
• Incorrect oil viscosity
• Inferior oil quality
COOLING SYSTEM (CS50Z only)
Coolant
• Low coolant level
Radiator
• Damaged or leaking radiator
• Bent or damaged radiator fin
Water pump
• Damaged or faulty water pump
• Thermostat
• Thermostat stays closed
• Oil cooler
• Clogged or damaged oil cooler
• Hose(s) and pipe(s)
• Damaged hose
• Improperly connected hose
• Damaged pipe
• Improperly connected pipe
EAS00856

OVERCOOLING (CS50Z only)

COOLING SYSTEM

Thermostat
• Thermostat stays open
EAS00859

POOR BRAKING PERFORMANCE

Disc brake
• Worn brake pad
• Worn brake disc
• Air in hydraulic brake system
• Leaking brake fluid
• Faulty brake caliper kit
• Faulty brake caliper seal
• Loose union bolt
• Damaged brake hose
• Oil or grease on the brake disc
• Oil or grease on the brake pad
• Incorrect brake fluid level
OVERHEATING / OVERCOOLING /
POOR BRAKING PERFORMANCE

FUEL SYSTEM

Carburetor(s)
• Incorrect main jet setting
• Incorrect fuel level
• Damaged or loose carburetor joint
Air filter
• Clogged air filter element

CHASSIS

Brake(s)
• Dragging brake
ELECTRICAL SYSTEMS
Spark plug(s)
• Incorrect spark plug gap
• Incorrect spark plug heat range
Ignition system
• Faulty ignitor unit
Drum brake
• Worn brake shoe
• Worn or rusty brake drum
• Incorrect brake camshaft lever position
• Incorrect brake shoe position
• Damaged or fatigued brake shoe spring
• Oil or grease on the brake shoe
• Oil or grease on the brake drum
• Broken brake torque rod
9-4
TRBL
SHTG